Apparatus for the production of screw threads by means of pressing rollers



Sept. 8, 1953 F. ERDELYI 2,651,224

APPARATUS FOR THE PRODUCTION OF SCREW THREADS BY MEANS OF PRESSINGROLLERS Flled Dec 19 1947 3Sheets-Sheet 1 Sept. 8, 1953" EL 2,651,224

F. 'ERD APPARATUS FOR THE PRODUCTION OF SCREW THREADS BY MEANS OF'PRESSING ROLLERS Filed De 19,-1947 a Sheets-Sheet 2 67 I IIH f 50a, I 542 I I I if an:

1 I I I I I 5 22 5a 53421 t 67 r I un $0 I I s 4 46 39 F. ERDELYIAPPARATUS FO T Sept. 8, 1953 R THE PRODUCTION OF SCREW 7 HREADS BY MEANSOF PRES-SING ROLLERS Filed Dec. '19, 1947 3 Sheets-Sheet 5 R r m m a M mmm M m A w B Patented Sept. 8

FOR THE SCREW THREADS BY APPARATUS ING ROLLERS Ferenc Erdlyi, FelsoWilhelm Fette. Hamburg-Altona,

god, Hungary, Prazisionswer Germany orFici-z MEANS, or PRESS- as signorto" kzeug-Fabrik,

Application December 19, 1947, Serial No. 792,666

Hungary December23 1946 2 Claims. (01. so 6) The invention relates to anarrangement for the production of screw threads, whereby the threads arepressed into the blank by means of position in which they In this mannerit becomes unnecessary to stop the apparatus upon completion of thethread pressing operation, or to turn back the blank and the tools inopposite direction until the tools disengage the blank.

It is an object of the means for the apparatus the thread rollerswhereby the thread rollers are with the length of the In accordance withthe invention the thread rollers are disposed upon eccentric shafts, sothat the radial displacement of the rollers can be effected by turningof the eccentric shafts of'the rollers.

Various means can be employed for radially displacing the eccentricshafts which bear the rollers in accordance with the length of thefinished thread. Two of these means are shown in the drawings asillustrative embodiments of the invention.

The principle of one of the sists of making the device of two parts,-oneof which carries the thread rollers and both of which are axiallymovable and rotatable relaembodiments con other upon separation of thedetents. This rotary movement is utilized for the displacement inventionto provide which operates with,

one another within predetermined limof the eccentric shafts of thethread rollers. The contact between the detent can be disengaged byaxial movement of the two part away from each other. For screws having ashort thread the length of the thread which is to be out. When the slidereaches this stop, that part of the device which carries the rollers, isdisplaced partial Fig. 5 is a view of the shaft of a thread roller witha gear forming a part thereof;

Fig. 6 is a longitudinal cross-section of the second embodiment of theinvention;

Fig. '7 is a plan view of the embodiment shown in Fig. 6; and

Fig. 8 is .a cross-section taken along line 8-8 of Fig. 1.

The device according to Figs. 1 to 4 has a hollow shaft I the left endof which is supported in the disk |3. Supported upon the shaft isgearwheel 3 which is adapted to engage gear wheels 4, 5 and 6 of thethree thread rollers G. Each thread roller is provided with ribs whichare pref erably in the form of helix. The gears 4, 5 and 6 are keyed tothe ends I of the'shafts 8o'f the rollers G. Each roller has anc'centrially'jour nalled shaft 8 (Fig. 5), which enables the approachingor removing of the rollers Gwith respect to one another by rotatingshaft 8' by means of its gear wheel. ported upon its respective shaftby, means. of a Each thread roller G is supball bearing 9. The studs ofthe shafts dare supported in corresponding bores in the disc The disc His connected to the disc l3 by'bolts' l2 which project through the disc2.

The part of the device thus far described is stationary during operationexcept for the thread rollers which turn on the blank while their axesare stationary.

The problem is to automatically interrupt the process of operation uponcompletion of the predetermined length of thread.

For this purpose a flange M is provided at the right hand endofthehollow shaft on which one end of the spring is supported. The other end.ofspring |5 rests against sleeve I6 which is disposed around the shaftl. and has an abutment H for the spring |5 in its interior. By virtureof this arrangement, compression spring l5 forces the sleeve |6- againstdisc |8. The disc I8, around'the periphery of which graduations areprovided for reasons set forth hereinafter, is keyed-to the shaft at IS.A detent is provided in the sleeve l6 which projects through a slot inthe disc I8 and rests againsta counterdetent 2|- on the disc l3. Thedescribed relative position ofthe parts mentioned is secured by thespring 22 providedinside of the device, one end of which, 25, isfastened to the disc 25' and" the other end, 2-'I-t0 the disc Hi Thede--' tents 20 and 2| overlap in the direction of the axis, so that inthe position shown the tensional spring 22 forces thetwo detents 2G, and2| against each other. The disc 26 is rotatable relatively to the disc|3 or thering 28 which holds together the discs Hi and 2 along theirperipheries.

The disc 18 is fastened'to disc 26 by means of bolt 29. Loosening bolt29 permits rotating of disc |8 relatively todisc 26. A slot for bolt. 29is provided in disc |8.for this purpose.

The shaft is provided withgear teeth 3i! which mesh with worm wheel 3|.Worm wheel 3] .can be. rotated by, means of head 32and spindle..33.whichcauses shaft. to be angularly displaced. Theextent of this displacement.can be read on the scale on disc I8 by means indicator on disc 26.

Theright hand end of-sleeve |6 is closed by a nut against which rests asecond nut 35 haying'a knurled periphery. Thetwo nuts are arranged upona spindle 31. which can be. rotated bym'eans of the head 36, 'Theendofthe spindle 3T'projects into the bore of shaft 1 The end of the spindle3j| .which.projects into of an.

the bore of the shaft forms an abutment the distance of which from therollers G can be adjusted by rotation of spindle 31. This abutment isadjusted in accordance with the length of the screw thread to beproduced. After the blank in its progressive movement reaches the end ofspindle 31 it carries along the sleeve It by way of nut 34. Thiscompresses spring i5. Also detent 20 moves to the right with sleeve l6until it leaves the right hand end of the counter-detent 2|. At thatmoment spring 2 2, is released and it carries along the cage constitutedof discs [I and I3 and bolts l2. The cage thus rotates while shaft anddiscs l8 and 26 remain stationary. Iguring rotation of the cage the gearwheels 4', 5 and ii of the rollers are turned by sagementwith. the gearwheel 3, thereby displacing the eccentric shaft of each roller.Consequently the thread cutting rollers G jump away radially'of the axisof the shaft and release "theblank'. Thus'upon completion of a thread ofpredetermined length the thread cutting rollers open-automaticallythereby solving the initial problem. Before a new blank is introduced itis necessary to return the tools to their operating position. Therefore,the cage formed intermediate the discs H and B is restored to theposition shown in the drawings in which position the detents 20 and 2|again rest against each other, For that purpose ring 28 is provided witha han' die 38. With the cage and the sleeve I B in sep-, aratedposition, ring 28 and with it the roller carrying member are turned tothe initial position whereupon the shell and the case are approached toeach other axially and the detents are placed adjacent each other. Forthis purpose detents 20 and 2| are preferably provided with slopingsurfaces which, while in engagement with each other, compel theseparation ofthesleeve lfi and the cage.

If it is desired to change the distance of the rollers from the axisofthe blank, bolt 29 is loos; ened and. worm wheel 3| isturned by, meansof head 32 until the scale on disc t8. indicatesthe position, correspoding to the new setting, where-- upon the bolt29 is again tightened.

For operating the device in the foregoing manner the device ispreferably supported in stationary position in, a lathe by securing thesleeve It; therein.

In accordance with the method described. it is possible to produce onlyrelatively short threads corresponding in length to shaft Thearrangement in accordance with the invention, however, is suitable for.the production of sub: stantially longer screws, or rather of screwsof.any desired length. For the purpose of producing, threads of anydesired, length theabutment 31; is first removed, 1. e. the nut isunscrewed. mmth e it. inc l fi h sna i iia shaft l is also open now,blanksof any v desilfii length can be passed throughthe shaft, There:upon the device is, fastened inthe ,slideof; a, lathe;preferablylengthwise of. the sleeve L6,, and the. travel ofthe slideislimited on the lathe to ;a-. distance corresponding to the length ofthread; which is tobeproduced. When upon completion of the operation theslide arives at the stop it ceases to move. However, since the tools Gcontinue to rotate, they movealong the thread and:-

pull that partofthe device which consistslofthe lem nt 2. 28. wand. i oa dfi je, leftsothatth is. p r aves the le ve Ilia,

arm-s24 intended to operate with such obliquely disposed ols, it is, ofcourse, necessary to construct the mesh of the gear wheels 3, 4, 5,

With the device Figs. 6 and 7 illustrate an embodiment which operateslikewise with thread rollers, but here the arrangement is set up in amanner that the device rotates preferably during operation while theblank remains stationary.

The screw is machined by the rollers 39. Each of these rollers ismounted upon an eccentrically journalled shaft 40. 4| are the rollers ofthe hearing. The eccentric trunnions 42 of the shafts are journalled ina ring 43 and the trunnions 44 in a disc 46 which forms a single piecewith the shaft 45. Each of the trunnions 44 has a striker pin 41disposed eccentrically with respect to axis 48 and engaging grooves 49aof the ring 49 (Fig. 7). Ring 49 is connected by means of bolts 59 toring 52 which is journalled to shaft 45 by way of the roller bearings5|. The bolts 50 project through the segment shaped slots in ring 52 sothat upon loosening the bolts 50 the two rings 49 and 52 can be movedrelatively to one another to the extent of the length of the slots.

Ring 52 has a cylindrical extension 53. A path in the form of a helicalslot 54 is provided in this extension. The path begins at the extremeedge of the cylinder 53 and ends in a stop paral lel to the axis T ofthe shaft 45.

A pin 56 formed as an integral part of a sleeve 58 is engaged by thehelical path 54, the sleeve 58 being adapted for axial displacement bying member 62.

Similarly to the arrangement according to the first embodiment a scale63 is provided around the periphery of disc 49 which can be read bymeans of index line 64 on disc 52.

Also in this embodiment the disengagement is obtained by turning theeccentric shafts 44 carrying the rollers when the disc 52 is rotatedwith respect to shaft 45, which causes the rollers 39 to be displacedradially. This displacement is eiTected by the pin 56 on sleeve 58.Thus, if the sleeve 58 is moved in the direction of the arrow 65 thedisc 52 turns on roller bearing 5| with respect to shaft 45 by virtue ofthe guide 54 and carries along the disc 49 by means of bolts 50.However, since the trunnions 44 are journalled in a flange 46 forming anintegral unit with shaft 45 or rigidly connected thereto and since pins47 of trunnions 44 engage slots 49a in disc 49 the pins 4! thus engagingslots 49a rotate and thereby rotate the eccentric shaft 40. Thisdisengages the tool.

After the disengagement the disc 52 may be returned to the startingposition by; movement of sleeve 58 in the opposite direction,

The disengagement means provided by means shaft 45 is rotating, for thesegments Bil are free the groove on ring 59.

trol of a stop; toa slide which length of a thread cut into the blank.

Having thus described and ascertained the nature of my invention and themanner in which it is to be performed, what I claim is:

ment means extending into said hollow shaft through the other endthereof and supported by said sleeve for engagement by the end of thework blank; a pair of cooperating detents one secured to said first partand the other to said sleeve, and a spring associated with said firstpart and said second part and disposed therebetween, whereby axialmovement of said abutment means moves said sleeve and disengages saiddetents and said spring rotates said first 10 part to move said rollersradially and release the work blank.

FERENC ERDELYI.

8 References Cited in the file of this patent UNITED STATES PATENTSNumber Name Date Moy et a1. Apr. 21,- 1908 Landis Feb. 8, 1910Breitenstein Oct. 30, 1928 Bysshe et a1. June 24, 1930 Williamson Feb.23, 1932 Bosworth Oct. 4, 1932

